More and more research is showing that good oral hygiene is important in more ways than one — it’s good not just for your mouth and teeth, but for your overall health as well. Earlier this year, researchers confirmed that brushing your teeth can reduce the risk of Alzheimer’s, as well as several other diseases. Now, a new study has uncovered another health benefit to brushing: good oral hygiene is also good for your heart.

A poor oral hygiene can have cascading effects. Not cleaning your mouth means that extra bacteria reach your gut and blood, causing inflammation in the body. Inflammation can cause several problems, including atrial fibrillation (irregular heartbeat) and heart failure (the heart’s ability to pump blood or relax and fill with blood is impaired). This study examined how strong this connection is, and how oral hygiene impacts these two conditions.

Researchers studied 161,286 participants of the Korean National Health Insurance System aged 40 to 79 with no history of atrial fibrillation or heart failure. Participants underwent a routine medical examination between 2003 and 2004, and information was collected on their physical parameters as well as oral health and oral hygiene routine. Then, they were tracked over a period of 10 years.

Tooth brushing three or more times a day was associated with a 10% lower risk of atrial fibrillation and a 12% lower risk of heart failure during 10.5-year follow up — even when corrected for age, sex, socioeconomic status, regular exercise, alcohol consumption, body mass index, and comorbidities such as hypertension.

It should be said that this is only a single study and it did not examine any mechanisms — in other words, it only examined correlation and not causation. Nevertheless, the large timescale and sample size lend it quite a bit of confidence, authors say.

“We studied a large group over a long period, which adds strength to our findings,” says senior author Dr. Tae-Jin Song of Ewha Womans University, Seoul, Korea.

However, the team does concede that they only analyzed participants from one country, which may skew the results.

“The strengths of this study presented by Chang et al.21 are the large sample size, with over 160,000 individuals included in the study, the large number of outcome events, and the long follow-up duration,” notes an accompanying editorial. “Nonetheless, this study has some limitations that need to be acknowledged.”

It is possible that the results could be accounted for by other variables (such as marital status, which has been shown to influence cardiovascular health). A bit more research is required to fully understand the causes and implications of the study.

But while it may be too early to recommend tooth brushing to improve your heart’s health, it’s yet another reason to keep healthy oral hygiene.

Journal Reference: Chang Y, Woo HG, Park J, et al. Improved oral hygiene care is associated with decreased risk of occurrence for atrial fibrillation and heart failure: A nationwide population-based cohort study. Eur J Prev Cardiol. 2019. doi:10.1177/2047487319886018.